ORGANS OF DIGESTION 1 49 



17. How much longer is the small intestine than the large one? 



1 8. On what does the length of the canal in different mammals largely depend? 

 ig. J\Iake a section of a portion of the wall of the stomach and draw what is 



seen, labelling all parts. 



20. Make a section of the small intestine, draw what can be seen by naked 

 eye or simple microscope. 



21. About how many villi to each square millimeter? 



22. Describe the two channels through which the food passes from the intes- 

 tines to the heart. 



23. Make a somewhat diagrammatic drawing representing that part of the 

 venous system conveying the food from the intestines to the heart. 



24. What is the size of the cecum in other mammals than the cat? 



25. Give the location, size, and form of the salivary glands. 



26. Name the lobes of the liver in order of their size. 



27. How is the liver held in place? 



28. Draw the pancreas, showing ducts leading to the intestine. 



29. Draw the complex stomach characteristic of many ruminants. 



30. What is the cloaca and in what mammals is it present? 



